Templates for facilitating the drawing of geometric figures, letters, and other images are well known. Draftsman commonly use such templates to conveniently and rapidly draw such geometric figures as rectangles, squares, and circles, as well as large block letters and the like upon paper when making mechanical drawings.
Such prior art templates typically comprise planar sections of rigid plastic having the appropriate shapes cut therefrom such that a pencil traced along the edge of a particular cutout will draw that image upon a sheet of paper. For example, when a draftsman desires to quickly form a box upon his drawing sheet, he may select a template having the appropriate size of rectangle formed therein and place that template at the desired location upon his drawing. The draftsman then simply places the tip of his pencil against the edge of the desired rectangle and traces the shape as required. Thus, desired images can be quickly and conveniently formed upon the drawing surface.
Additionally, templates and stencils are known for forming various images for artistic or ornamental purposes. For example, a solid image of a bird in flight may be cut into a sheet of paperboard and subsequently used for painting that image upon various surfaces. The paperboard could, for example, be placed in laminar juxtaposition to a wall upon which a mural is being painted and then used to form the image of the bird in flight thereupon. This can be accomplished by holding the stencil in place while spray painting, roller painting, brush painting, or otherwise applying a layer of paint through the stenciled cutout to form an image upon the wall. Those skilled in the art will appreciate that numerous appliances and applications exist in the art of stenciling of images upon surfaces.
In their above-referenced co-pending parent patent application for THREE-DIMENSIONAL DRAWING DEVICE, Applicant disclosed a drawing device for forming images upon the inside of a hollow transparent spherical drawing surface which is primarily intended for use as a teaching aid and toy. The THREE-DIMENSIONAL DRAWING DEVICE comprises a transparent hollow sphere, a powder material disposed within the sphere which adheres to the inner surface of the sphere, a scribe disposed within the sphere which can be used to draw upon the inner surface of the sphere by scraping off the powder material, and controls for manipulating the scribe such that images may be formed upon the inner surface of the sphere.
The controls for manipulating the scribe comprise a first control knob for positioning the scribe relative to the sphere in azimuth by rotating the sphere about its vertical axis, a second control knob for positioning the scribe relative to the sphere in altitude by rotating the scribe about a horizontal axis which is perpendicular to the longitudinal axis of the scribe, and a scribe retractor control for removing the scribe from the inner surface of the sphere to permit repositioning of the scribe.
As discussed in Applicant's co-pending parent patent application, a list of control positions can be provided to enable the user to reproduce a desired image upon the sphere, however, use of such a list of control positions can be somewhat difficult, especially for younger users Thus, it would be desirable to provide a means by which images may be traced when using the THREE-DIMENSIONAL DRAWING DEVICE.